Answer
A.
Work Step by Step
The interior of a phospholipid bilayer is hydrophobic due to the presence of the hydrophobic fatty acid tails from the phospholipids. The hydrophilic part is the outside of the bilayer, making B. wrong, and the interior is nonpolar, eliminating C. D. could be true for some membranes, but there are usually some unsaturated lipids in the membrane, making D. incorrect as a general principle.
